1. Field of the Invention
The invention relates to remote monitoring systems and is directed more particularly to a ballast water exchange monitoring and reporting system, to a substantially wireless monitoring and reporting system, and to a marine voyage data recorder system.
2. Description of the Prior Art
While the increase of sea borne commerce over the last century has contributed significantly to the economic development of almost all nations, it has also increased the vulnerability of native echosystems, as well as local economies, and public health associated with them. The threats come from the release of xe2x80x9cNon-Indigenous Speciesxe2x80x9d into the marine environments from ballast water discharge of ships during loading of cargoes at various ports.
Normally ships sail at a designated gross tonnage to reduce stress on their hulls, and maintain safe stability and maneuverability. However, the tonnage reduces when cargo is unloaded or as water and fuel is consumed during a voyage. Ballast water is taken in when cargo is unloaded or fuel tanks are emptied, to maintain acceptable tonnage. Ballast water is thus essential for the safe operation of ships. As cargo and fuel are loaded in the next port of call, the ballast water taken in earlier is discharged. Unfortunately, during the discharge various marine micro-organisms taken in during ballast loading are discharged into a new environment and can pose numerous threats.
There are a number of examples of such threats, including the introduction of North Pacific Seastar (Asterias amurentis) in Australia from ballast water taken in Japan. This predatory species poses a threat to the local commercial shellfish industry. Another example is the presence of the European Zebra Mussel, (Dreisseina polymorpha) in the United States. Introduced in the Great Lakes in the 1980s, it is currently detected in 40% of inland United States waterways, fouling water intake pipes, and has cost over $5 billion (estimated) in associated cleanups since 1989. Further, ballast water can be a potential bio hazard as demonstrated by the discovery of the cholera bacterium in the oysters and shellfish of Mobile, Ala., brought by ballast water exchange during the South American cholera epidemic in 1991.
Recognizing the risks, the United States Congress has passed the National Invasive Species Act of 1996 (NISA) which requires ships entering United States waters from outside the Exclusive Economic Zone (EEZ) to report ballast water management practices.
There are recognized methods to reduce threats from Aquatic Nuisance Species, including:
1. Isolation, which involves discharging the ballast water into special reception facilities, or returning the water to its original location.
2. Treatment, which involves treating the water properly before discharging the water. Treatment options are mechanical (e.g. filtration), physical (e.g. thermal, ultraviolet, etc.) and chemical (e.g. use of various disinfectants or organic biocides).
3. Exchange, which involves flushing of the ballast tanks in deep water.
Of the above three methods, only ballast water exchange is economical at present and is the focus of the United States Coast Guard which has instituted a voluntary program for ballast water management based on ballast water exchange and reporting for vessels coming from outside the EEZ. The program may become mandatory in the future.
Ballast water can be carried either in dedicated ballast tanks or in specially designed cargo holds. Some typical locations of ballast tanks T are shown in FIGS. 1 and 2, wherein WL indicates the water line of a fully loaded vessel.
As seen in FIGS. 1 and 2, the ballast tanks can be located in different parts of the ship, depending upon the design of the specific class of ships. The primary purpose of the ballast tanks is to provide stability in all possible cargo loading combinations when the vessel is underway or is loading or discharging cargo at ports. To support this need, a ballast piping system, consisting of ballast pumps and distribution piping and valves, interconnects the ballast tanks. For the ballast water exchange program, the Coast Guard recommends two exchange methods, namely xe2x80x9cempty-refillxe2x80x9d method and xe2x80x9cflow-throughxe2x80x9d method. In the empty-refill method, a ballast tank is emptied first and then filled with ocean water. In the flow-through method, discharge and pumping of water is executed simultaneously in a ballast tank and the process is considered complete after a three-tank volume of water is discharged. Of the two methods, generally the xe2x80x9cempty-refillxe2x80x9d method is more risky for ship""s stability, but the master of the vessel has the final authority on how to conduct ballast exchange.
To ensure compliance with NISA, the United States Coast Guard has introduced mandatory ballast water reporting for all vessels entering the EEZ, although the overall ballast water management program remains voluntary. Vessels are asked to perform voluntary mid-ocean ballast exchange and report it when they enter the next port. The reporting form requires a history of ballast tank activities, such as where the tanks were filled and how much, where in the ocean the exchange took place, the water temperature, etc. There is also a provision requiring a statement as to the reason if an exchange was not performed. The reports are sent to the National Ballast Information Clearinghouse (NBIC), a collaborative data management and analysis center, run by the United States Coast Guard and the Smithsonian Environmental Research Center. Over the first twelve months (Jul. 1, 1999, to Jun. 30, 2000) of the rule, compliance with reporting was only 20.8%, as per NBIC interim report. As it stands now, even when reports are provided, the authenticity of the geographical location where the exchange has taken place cannot be verified.
It is clear that an automated system is needed which will be able to produce the ballast water exchange reports more comprehensively and accurately with automatic integration of navigation. Some general requirements that the ballast water exchange monitoring system should be able to satisfy are:
1. The system should be scaleable and be able to integrate into the most basic ships, and to high-end vessels.
2. The system must be easy to install and operate.
3. The system should be versatile and be capable of providing other information that may be needed, such as water temperature or salinity in ballast tanks.
An object of the invention is, therefore, to provide a ballast water monitoring and reporting system which is adaptable to virtually all vessels, large and small, is relatively inexpensive and easy to install and operate, and which is capable of providing and recording other information, such as the status of hull integrity, fire doors, watertight doors, and the like, and which can be coordinated with navigational position systems to provide a record of locations of events detected and recorded.
A further object of the invention is to provide for the automatic generation of accurate ballast water reports acceptable to the United States Coast Guard and similar governmental agencies of other countries.
A still further object of the invention is to provide a wireless system for monitoring conditions in large structures having a metal structural component extending substantially throughout the structure, the system being operable to monitor conditions in sea-going vessels, as noted above, but also being operable to monitor other structures, such as buildings, bridges, cranes, aircraft, and the like.
With the above and other objects in view, a feature of the present invention is the provision of a ballast water monitoring and reporting system for seagoing vessels. The system includes a sensor for monitoring a selected parameter of a ballast water system component and for transmitting an electronic signal indicative of a condition of the selected parameter, a distal acoustic modem for receiving the signal from the sensor and for creating and transmitting an acoustic signal equivalent to the electronic signal received, a shipboard metal structure extending substantially throughout the vessel and adapted to carry the acoustic signal, a proximal acoustic modem adapted to receive from the metal structure the acoustic signal created and transmitted by the distal acoustic modem, and to transmit an electronic equivalent thereof, and a shipboard data acquisition computer adapted to receive the electronic signal from the proximal acoustic modem and to generate at least one of a display, a report relative to the selected parameter, and a recording of data relative to the selected parameter.
In accordance with a further feature of the invention, there is provided a system as described immediately above wherein the data acquisition computer is adapted to receive inputs from a position system unit and to include data therefrom in the display, paper report, and recording.
In accordance with a still further feature of the invention, there is provided a marine voyage data recorder system for seagoing vessels. The system includes sensors disposed on the vessel in selected locations for monitoring selected parameters and for transmitting electronic signals indicative of conditions of the selected parameters, distal acoustic modems for receiving the signals from the sensors and for transmitting acoustic signals equivalent to the electronic signals received, a shipboard metal structure extending substantially throughout the vessel and adapted to carry the acoustic signals, a proximal acoustic modem adapted to receive the acoustic signals from the metal structure and to transmit electronic equivalents thereof, and a voyage data recorder adapted to receive electronic signals from the proximal acoustic modem and to record data carried by the electronic signals from the second acoustic modem.
In accordance with a still further feature of the invention, there is provided in the system described immediately above a navigation position system unit, and the voyage data recorder is adapted to receive inputs from the position system unit and to record the data therefrom in conjunction with recordal of the data from the proximal acoustic modem.
In accordance with a still further feature of the invention, there is provided a substantially wireless monitoring and reporting system for structures having a metal structural component extending substantially throughout the structure. The system includes a sensor for monitoring a selected parameter in a selected location in the structure and for transmitting an electronic signal indicative of a condition of the selected parameter in the selected location, a distal acoustic modem for receiving the signal from the sensor and for transmitting an acoustic signal equivalent to the electronic signal received, to the metal structural component and through the metal structural component, a proximal acoustic modem adapted to receive the acoustic signal transmitted through the metal structural component and to transmit an electronic equivalent thereof, and a data acquisition computer adapted to receive the electronic signal from the proximal acoustic modem and to generate at least one of a display, a paper report relative to the selected parameter, and a recording of data relative to the selected parameter.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular system embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.